Uneven, Uneven, ConchoidalAnthony et al, Handbook of mineralogy (2001), Conchoidal, Uneven
Uneven, Uneven, ConchoidalWalter Schumann, Gemstones of the world (2001)
Mn 3B 7O 13ClMichael OâDonoghue , Gems, Sixth Edition (2006)
Mg 2Al 4Si 5O 18Ulrich Henn and Claudio C.